The primary objective is to determine whether, for men at above average risk of death from coronary heart disease, a special intervention program will result in a significant reduction in mortality from coronary heart disease. To achiev e this objective a screening program will be conducted to identify approximately 12,000 men aged 35-57 who are in a upper percentile of the distribution of risk for death based on risk factors of elevated serum cholesterol, elevated diastolic blood pressure, and cigarette smoking; and who do not have pre-existing definite clinical coronary heart disease, or other specified causes for exclusion; and are willing to commit themselves to a 6-year intervention program of study.